In order to clarify whether a combination of designs is optimal, design elements are divided intodesign variables and random variables in the inquiry process for the optimal design. Design variablesrelated to the model are selected by a genetic algorithm, and random variables related to outdoor condition are selected by the moment method. The whole process of optimization consisted of a two-step procedure to reduce the calculation loads for finding the optimal solution. This study carried out a simple analysis using a coarse mesh considering the calculation loads in the first step.

We describe the results of simple modelling and some laboratory experiments of the natural ventilation flows which can develop in an office building when air is supplied from a central atrium, passes through the floor-space of the building, and then vents through stacks at the perimeter of the building.

Evaluating naturally ventilated buildings for performance is a difficult task, often relying oncomputer simulations and modeling to assess thermal comfort and airflow issues. This paper presents the long and short term monitoring procedures and data devised to determine the overall building performance of a naturally ventilated office building in the United Kingdom.

Predicting the performance of natural ventilation is difficult, especially for the large scale naturally ventilated buildings, because of the lack of accurate and efficient prediction tools. This paper presents a strategy, integrating a multi-zone model and computational fluid dynamics (CFD), to improve natural ventilation prediction and design. Large openings and atrium are broadly used in naturally ventilated buildings to promote buoyancy force and optimize air movement. How to properly deal with large openings and atrium is discussed and compared in this paper.

Natural ventilation is a more pleasant and acceptable ventilation mode, which is favorable to human physical and psychological comfort and health. In this research, experiments and analysis on the fluctuant characteristics of natural wind in outdoor environment and in different positions of indoor area are conducted. The authors analyze the physical structure of airflow fluctuations with turbulence statistical theory, chaos and fractal theory. The fluctuant characteristics of the natural wind in different built environment are found and generalized in the paper.

When designing natural ventilation for complex buildings, it is key to understand whether there is a unique solution for the flow, or if multiple flow regimes are possible. Here, we show that in a 2 storey open plan office type building, in which the floors are connected to a common atrium, two stable flow regimes may occur under identical conditions.

The aiflows driven by a revolving door that links two rooms of initially uniform temperature are examined. Two situations are considered, the first in which the rooms are at equal temperature, and the second in which there is a temperature difference between the rooms.
The flows were examined using a small-scale model of a revolving door and with fresh- and
salt-water solutions to represent temperature differences. The results presented herein reveal
how the transfer of air across a revolving doorway depends on the rotation rate and temperature

As part of an investigation into single-sided natural ventilation, a computational fluid dynamics study was performed to analyse the impact on the airflow rate of the dimensions and position of a large rectangular opening and of the temperature difference between inside and outside air. An empty room with a rectangu-lar opening in the external wall was assumed and the Bernoulli formula used to calculate discharge coefficients Cd. The vertical position of the opening was found to have the greatest impact on the discharge coefficient.

The fluctuating characteristics of airflow have impacts on the thermal comfort of people. Two kinds of mechanical airflows in indoor environment were tested and analyzed in the paper. Spectrum analysis, chaos analysis were used to study the rule of the fluctuating characteristics shifting of the mechanical airflows. The results show that the fluctuating characteristics of different kinds of mechanical winds are different. It is also found that the characteristic parameters of the mechanical airflow, such as power spectrum etc.

The air exchange rate is a determinant factor for the indor air quality in a given spaces. If it is lower than the required it may cause the so caled sick building syndrome. The ultimate result depends, obviously, also on the nature and strength of the sources emisions. In this work the natural